#app2 .tab-bar {
    display: flex;
}

#app2 .tab-bar>li {
    border: 3px solid red;
    width: 50%;
}

#app2 .tab-bar>li.selected {
    background: #f00;
    color: yellow;
}

#app2 .tab-content>li {
    display: none;
}

#app2 .tab-content>li.active {
    display: block;
}